FR2901087A1 - Digital film reading device, has composite image generator generating composite images from images extracted by extraction module and controlling display of extracted image corresponding to specific instant associated with time marker - Google Patents

Abstract

The device has a control module (24) for controlling a display of digital film read by a reading module (22) on a display screen (4) e.g. television. An image includes a time marker associated to a specific instant. An image extraction module (40) extracts a sequence of images corresponding to a specific instant. Composite image generator (42) generates composite images from the images extracted by the module. The generator controls the display of extracted image corresponding to the specific instant associated with the marker. Independent claims are also included for the following: (1) a method of reading data (2) a recording support comprising a set of instructions for executing a method for reading a data (3) a computer program comprising instructions for executing the method for reading the data (4) a data carrying signal representative of an image produced by a composite image generation unit.

Description

The present invention relates to a device and method for accessing

  quickly at a moment in a sequence of images. There are readers adapted to advance and / or return rapidly in steps in a film, which is understood here as a video work regardless of its content, and may for example consist of a temporal sequence of successive images. With these players, film images temporally spaced apart from each other by regular intervals are displayed one after the other in their chronological order of appearance in the film. A value of the regular interval is chosen according to the desired speed of advance and / or return. Therefore, to advance from a time td corresponding to the beginning of the filrn until a time tf at the end of the film, the player scrolls a temporal succession of intermediate images between these times td and tf. More recently, readers using time markers have been proposed to avoid this scrolling of intermediate images. Typically, in these newer readers, the time markers are aligned one after the other and form the graduations of a time-displacement slider. A cursor visible on the image is movable by the user from one graduation to another. When the user has moved the cursor to the desired position on the slider by pressing a button on a remote control several times, the player starts to read the movie from the moment corresponding to the graduation pointed by the cursor. Thus, thanks to these readers, it is possible to advance a moment td at a time tf without scrolling intermediate images between these times td and tf. However, the graduations used in these readers do not make it easy to locate a precise moment of the film until the user wants to advance or return quickly. For example, the user may wish to advance quickly to the end of an advertisement inserted in the middle of the recorded movie. For that, with the existing readers, it must proceed by successive iterations until being able to point the cursor on the graduation corresponding to the end of the advertising sequence. The need to proceed by successive iterations makes these readers difficult to use. The present invention offers a solution that does not have these disadvantages by providing, in a first aspect, a reading device adapted to advance and / or return quickly at a time tf with time markers easier to use.

  The object of the invention is indeed a device including means for rapidly accessing a time tf of a sequence of images of which said data are representative, which time is intended to be chosen by a user of said device, this device including display means of an image containing at least one time marker associated with a specific instant t ;, said device being provided with acquisition means, as chosen instant tf, of a time t; associated with a time marker actually selected by the user, characterized in that it comprises: - extraction means (40) of an image of the sequence corresponding to a specific time t ;, and - means generating (42) composite images capable of controlling a display, within each marker, of the extracted image corresponding to the instant t; specific associated with this marker. Thanks to the images in the markers, the user can more easily locate the instant tf of the film to which he wants to return or advance quickly. This facilitates the use of advance and / or fast return. The embodiments of this device may comprise one or more of the following characteristics: means for moving a cursor in the image in response to displacement commands, this cursor being able to point to one of the markers, means for acquiring a validation signal, and reading means able to begin to read the sequence of images directly from an instant t; associated with a marker pointed by the cursor at the time of acquisition of the validation signal; the generation means are capable of controlling the display of a marker table formed of several rows and of several columns, each row and each column containing a succession of markers arranged in chronological order, the instants t; associated with the markers of the same line forming an arithmetic progression of reason ri and the instants t; associated with the markers of the same column forming an arithmetic progression of reason r2, the reasons ri and r2 may be different from each other.

  These embodiments of the device according to the invention also have the following advantages: by virtue of the presence of a marker array formed of several rows and columns, it suffices to press a single key, on the one hand, to choose the speed of fast forward and rewind used to move in the film and, on the other hand, to indicate the direction of travel, that is to say forwards or backwards, and - to use ri and r2 different reasons can offer the user two different speeds of movement. The invention also relates to a data reading method for quickly accessing a time tf of a sequence of images of which said images are representative. This method comprises: a step of displaying an image containing at least one time marker associated with a specific time t; and an acquisition step, as selected instant tf, of a time t ; Associated with an actually selected time marker, - a step of extracting an image of the sequence corresponding to a specific instant t ;, and - a step of generating the extracted image corresponding to the instant t; specific associated with this marker. The embodiments of the method above may comprise one or more of the following features: a step of moving a cursor in the image in response to displacement commands, this cursor being able to point at one markers, a step of acquiring a validation signal, and a step of controlling the reader so that the latter begins to read the film directly from the instant t; associated with the marker pointed by the cursor at the time of acquisition of the validation signal; 4 - a step of controlling the display of a marker table formed by several rows and several columns, each row and each column containing a succession of markers arranged in chronological order, the times t; associated with each marker of the same line forming an arithmetic progression of reason ri and the instants t; associated with each marker of the same column forming an arithmetic progression of reason r2, the reasons ri and r2 may be different from each other. The invention also relates, according to yet another of its aspects, a recording medium and a computer program comprising instructions for the execution of the above method, when these instructions are executed by an electronic computer. In addition, the invention also relates, as a product obtained directly during its implementation, to a signal carrying data representative of at least one image produced by composite image generating means in accordance with the description which precedes . The invention also relates, as a means useful for its implementation, a control element of reading means of a sequence of images characterized in that it comprises: - a module for extracting images from the sequence corresponding to different times t; intended to be associated with different time markers, and - a composite image generator capable of controlling the display, within each marker, of the extracted image corresponding to the instant t; specific associated with this marker.

  The invention further relates, as another means useful for its implementation, a reading apparatus including means for quickly accessing a given instant of a sequence of images associated with a time marker selected by a user of the apparatus, characterized in that it comprises: extraction means (40) of at least one image of the sequence corresponding to a specific moment chosen by a user of the apparatus and intended to be associated with a time marker, and - means for generating (42) at least one composite image capable of controlling a display, within at least one marker included in said composite image, of the extracted image corresponding to the specific time associated with this marker. Depending on the embodiment chosen, the display means may or may not be integrated within the apparatus described above. The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings, in which: FIG. 1 is a schematic illustration of the architecture of a device for digital movie playback suitable to advance and / or return quickly at a time chosen by the user of the film - Figure 2 is a flowchart of a method of advance and / or fast return implemented in the player of Figure 1; and FIGS. 3 and 4 are illustrations of composite images presented to the user during the implementation of the method of FIG. 2. FIG. 1 represents a device according to the invention, which includes a reader 2 of FIG. digital movies connected to a display screen 4, such as that of a television.

  The reader 2 is a remotely controllable device from a remote control 6. The reader 2 is, for example, a digital video recorder equipped with a hard disk 10. The hard disk comprises a recording medium 12, such as one or more magnetic or optical discs on which digital data can be recorded. At least one digital film is recorded on the medium 12, for example in the form of magnetic or optical inscriptions. Digital film is made up of coded audio and video signals. The hard disk 10 also includes one or more read heads. To simplify FIG. 1, only a read head 14 has been represented. The head 14 is mounted on a movable read arm 16. Each film is recorded on the support 12 in a standardized digital format, such as, for example, the Moving Pictures Expert Group (MPEG) format 2 or 4. The support 12 and the head 14 are movable one opposite each other. of the other so as to allow a jump of a recording area of the medium 12 containing bits of a first sequence of the film to another recording area containing bits of a second sequence of the film without having necessarily to move the read head over all the recording areas containing bits of the intermediate sequences of the film located temporally between the first and the second sequences. The reader 2 also comprises a card 20 for processing the audio and video signals recorded on the hard disk 10. This card 20 comprises more specifically: a module 22 for reading the film recorded on the hard disk 10, a control module 24. the display of the film read by the module 22 on the screen 4, and - a control element 28 of the reading module for fast forwarding or returning to a selected instant tf in the film.

  Typically, the card 20 is made from programmable electronic computers capable of executing instructions recorded on an information recording medium. For this purpose, the card 20 is connected to an information recording medium, represented here by a memory 30 containing instructions for executing the method of FIG. 2.

  The modules 22 and 24, the control element 28 and the memory 30 are connected to each other via an information transmission bus 32. The reading module 22 is able to transform the film recorded in the hard disk 10 into a video stream furthermore formed of a succession of images. More specifically, the video stream comprises a temporal succession of images appearing one after the other, each image being temporally separated from the image which precedes it by a refresh interval dr. Typically, the interval 4 is less than 1/50 of a second. In this video stream, each image appears at a time tt set from the encoded video signal recorded on the hard disk 10. The time t1 is counted from a predetermined time to the film. For example, here, the instant to corresponds to the moment at which the first image of the recorded movie appears. The moment to corresponds to the beginning of the film. Thus, each image is associated with a time ti to which it must be displayed on the screen 4 when the film is running at normal speed. The module 22 is therefore in charge of a large number of tasks such as, for example, the tasks of decompressing the digital film recorded on the hard disk 10 if it is compressed. The control element 28 is able to control the read module 22 so that from a current instant tc the module 22 advances or returns quickly to a time tf of the film chosen by the user. The instants tc and tf are instants identified with respect to the film read by the module 22. For example, here, the instants t.c and tf are counted from the moment to. The instant tc is equal to the instant ti of the image currently displayed on the screen 4. The instant tf is equal to the instant ti associated with an image that has already been read by the module 22 in the case a return back or will be read later by the reader 22 in the case of a fast forward.

  To determine the instant tf, the control element 28 furthermore comprises: a module 40 for extracting images located at predetermined time intervals in the film; a generator 42 for composite images from the images; extracted by the module 40, - a module 44 for moving a cursor in the generated composite image, and - an interface 46 adapted to acquire control signals sent by the remote control 6.

  More specifically, here, the extraction module 40 is able to extract images at regular intervals 4, in the film. Typically, dp is greater than 20 seconds and less than 20 minutes. Here 4 is chosen equal to 30 seconds. The remote control 6 is adapted to send control signals via a wireless link 50 to the interface 46 in response to the pressing of a key. For this purpose, the remote control 6 comprises: - a key 52 for triggering the sending of a signal for activating the advance and / or a fast return, 8 - four keys 54 to 57 capable of triggering the sending cursor movement signals, and a validation key 60 to trigger the sending of a validation signal.

  The keys 54 and 55 correspond to a horizontal displacement of the cursor respectively to the left and to the right. The keys 56 and 57 correspond to a vertical movement of the cursor respectively upwards and downwards. The operation of the control element 28 will now be described with reference to FIGS. 2 to 4. Initially, during a phase 70 of reading of the film at normal speed, the module 22 transforms, during a step 72, the digital film recorded on the hard disk 10 in a video stream transmitted to the module 24. In parallel, during a step 74, the module 24 controls the display image by image on the screen 4 of the video stream. For example, the module 24 controls the display of the images on the screen 4 as it receives them. Thus, the order of the images and the temporal relation between the images contained in the video stream are preserved during the display on the screen 4. During the phase 70, the film is displayed in full screen, on the screen 4.

  At any time during the course of the film at normal speed, a user can trigger a phase 78 in advance or fast return to a time tf of the film. At the beginning of the phase 78, at the current instant t, of the film, the user presses, during a step 80, the key 52. In response, during a step 82, the remote control sends the signal of activating the advance or the fast return to the reader 2. During a step 84, the interface 46 acquires the activation signal sent. In a step 86, in response to the activation signal, the control element 28 reads the current time tc corresponding to the image currently displayed on the screen 4. Then, during a step 88, the control element 28 orders the stopping of the module 22, so as to temporarily interrupt the reading of the film.

  Once the film has been stopped, during a step 90, the extraction module 40 calculates all the times ti spaced from each other by the interval AI, using the following relation: ## EQU1 ## with ti E [t .; [1] where: - 1 represents the absolute value operator, - n is a positive integer, -. represents the multiplication operation, and - tends corresponds to the last image of the recorded movie.

  Then, during a step 92, the module 40 extracts from the hard disk 10 the images of the film corresponding to the instants ti calculated. In a step 93, from the extracted images, the generator 42 builds one or more composite images. Since the structure of the composite images is the same regardless of the composite image displayed, only a composite image 94 shown in FIGS. 3 and 4 will be described here in detail. The composite image 94 comprises several time markers 96, here twenty markers 96. Each marker is associated with one of the instants ti calculated during step 90. These markers 96 are placed in the composite image 94, some to next to others in the chronological order of their moments ti with which they are associated. Specifically, here, the markers 96 are contained in a table consisting of five vertical columns 100 to 105 and four horizontal lines 106 to 109. Each marker 96 is placed at the intersection of a line and a column.

  The marker associated with the smallest time ti is placed at the top left at the intersection of the column 100 and the line 106. In contrast, the marker 96 associated with the instant t; the largest is placed at the bottom right in the image 94 at the intersection of the column 105 and the line 109. The interval of time separating two successive markers on the same line is equal to Ap while the interval The time interval separating two successive markers in the same column is equal to 5. Thus, the sequence of times ti associated with each marker of the same line form an arithmetic progression of reason 4 and the sequence of times t; associated with each marker of the same column form an arithmetic progression of reason 5. 4,. The generator 42 builds a sticker 98 for each extracted image corresponding to a time t; calculated. Each thumbnail is a small replica of the corresponding extracted image. Thus, each vignette 98 corresponds to a time t; The generator then places each thumbnail 98 corresponding to a time t; within the associated marker 96 at the same time t ;. The image 94 also includes a slider 112 and, optionally, a moving key 115B. The cursor 112 is able to point to one of the markers 96 of the image 94. For example, here, the cursor 112 surrounds the marker 96 that it points. The position of the cursor 112 in the image 94 is determined by the module 44 as a function of the displacement signals sent by the remote control 6. By default, initially, the cursor 112 is positioned around the associated marker at the current time tc. The vertical displacement bar 115A represents the time course of the film between the times to and tends. The movement key 115B indicates the time position on the bar 115A of the instant t; associated with the marker on which the cursor 112 points. Once the image 94 is constructed, in a step 114, the generator 42 controls the module 24 to display the image 94 on the screen 4. Immediately thereafter, when a step 116, a timer is triggered. This timer counts a predetermined time interval equal, for example, to one second. At the end of the time counted by the timer, if the cursor 112 has not been moved, during a step 118, the control element 28 orders the resumption of the reading of the film from the instant t ; corresponding to the marker currently pointed by the cursor 112. After step 118, during a step 120, the control element 28 controls the module 24 to display the video stream read inside the marker pointed by the cursor 112 instead of the sticker 98 that was there. Thus, inside the marker pointed by the cursor 112, after a second of waiting, the user sees the film unfolding from the instant t; corresponding to this marker. If the cursor 112 is moved before the entire countdown by the timer has elapsed, this timer is reset. In parallel, when the image 94 is displayed, the user can press one of the keys 54 to 57, during a step 122. In response to the depression of one of these keys, during a step 124, the remote control 6 sends a signal for moving the cursor to the reader 2.

  The interface 46 acquires this signal during a step 125. Then, during a step 126, the module 44 controls the module 24 to move the cursor 112 as a function of the acquired displacement signal. For example, as shown in FIGS. 3 and 4, if the user pressed the key 55, in the step 126, the cursor 112 is moved to point to the marker immediately to the right of the previously pointed marker. Steps 122 to 126 are repeated until the user has moved the cursor 112 to point to the desired marker. Then, during a step 128, the user presses the validation key 60. In response, during a step 130, the remote control 6 sends a validation signal to the reader 2. This validation signal is acquired during a step 132 by the interface 46. The control element 28 then acquires during a step 134, the time t; corresponding to the marker currently pointed by the cursor 112. The instant tf is now equal to the instant t; acquired.

  Then, during a step 136, the control element 28 orders the resumption of the reading of the film directly from the moment tf acquired during the step 134. For this purpose, for example, the element of control 28 controls the module 22. In the step 136, the read head 14 of the hard disk 10 is, for example, directly moved from the recording area containing the image corresponding to the instant t, to the zone record containing the image corresponding to instant tf. At the end of step 136, the reader returns to the reading phase 70 of the film. Many other embodiments are possible. For example, the control element 28 can also acquire control signals via a menu displayed on the screen 4 or buttons integral with the reader 2.

  The hard disk 10 and the control element 28 may be in separate boxes connected to each other via a local area network or a long distance information transmission network. The hard disk 10 can be replaced by an optical disk drive such as, for example, CD-ROMs or DVDs (Digital Versatile Disc). The hard disk can also be replaced by any other type of mass memory allowing direct access to a memory block such as RAM (Random Access Memory). The markers 96 are represented in the image 94 as a border surrounding the thumbnails. However, it is not necessary that such borders be visible. Indeed, the marker may be limited to the space strictly necessary to display the sticker 98. The validation button 60 may be omitted. In this case, the validation signal is automatically generated if the cursor 112 points continuously to one of the markers for a time greater than a predetermined threshold SI.

  Finally, it is possible to provide several levels of navigation, each level comprising the display of a composite image using an interval 4, reduced from the upper level. For example, in a first level, the interval used dp is equal to 15 minutes. When the user selects a marker associated with a time tp, the control element 28 orders the display of the composite image of the lower level in which the interval d used is, for example, equal to one minute. Moments t; associated with the lower level markers are based on the time tp selected at the higher level. For example, the moments t; are calculated using the following relationship: lt; where n is an integer belonging to the set [1; ...; 10], 13 - tp is the moment selected at the higher level, this instant tp being itself a function of the current time tc where the user has activated the device 28. When a marker of the lower level is selected, the Playback of the movie in normal view starts from the moment associated with the selected marker. Preferably, only the images necessary for the construction of the composite image to be displayed are extracted, which limits the number of images of the film to be extracted. Alternatively, the interval dp is not constant. For example, the interval d increases as the extracted images are moved away from the current time tc. Thus, alternatively, the sequence of times t; markers of the same line or the same column of the image 94 form a geometric or logarithmic progression.

Claims (3)

  1. Device including means for rapidly accessing a time tf of a sequence of images of which said data are representative, which time is intended to be chosen by a user of said device, this device including display means (24) an image (94) containing at least one marker (96) of time associated with a specific time t ;, said device being provided with acquisition means, as chosen instant tf, of a time t; associated with a time marker actually selected by the user, characterized in that it comprises: - extraction means (40) of an image of the sequence corresponding to a specific time t ;, and - means generating (42) composite images capable of controlling a display, within each marker, of the extracted image corresponding to the instant t; specific associated with this marker.   2. Device according to claim 1, characterized in that it comprises: - means for moving (44) a cursor (112) in the image in response to displacement commands, this cursor being adapted to point to one of the markers, acquisition means (46) for a validation signal, and reading means (22) capable of beginning to read the sequence of images directly from the moment. t; associated with a marker pointed by the cursor at the time of the acquisition of the validation signal.   3. Device according to claim 2, characterized in that the generating means (42) are able to control the display of a marker table formed of several lines (106 to 109) and several columns (100 to 105). each line and each column containing a succession of markers arranged in chronological order, the instants t; associated with the markers of the same line forming an arithmetic progression of reason ri and the instants t; associated with the markers of the same column forming an arithmetic progression of reason r2. 4, Device according to claim 3, characterized in that the reasons ri and r2 are different from each other. 5. Control element means for reading a sequence of images, characterized in that it comprises: a module (40) for extracting images of the sequence corresponding to different times t; intended to be associated with different time markers, and - a generator (42) of composite images capable of controlling the display, within each marker, of the extracted image corresponding to the instant t; specific associated with this marker. 6. Reading apparatus including means for quickly accessing a given moment of a sequence of images associated with a time marker selected by a user of the apparatus, characterized in that it comprises: extracting (40) at least one image of the sequence corresponding to a specific moment chosen by a user of the apparatus and intended to be associated with a time marker, and - generation means (42) of at least one composite image capable of controlling a display, within at least one marker included in said composite image, of the extracted image corresponding to the specific instant associated with this marker. 7. A method of reading data enabling rapid access to a time tf of a sequence of images of which said data are representative, this method including: a step of displaying (114) an image containing at least one time marker associated with a specific time t ;, and - an acquisition step (134), as chosen instant tf, of a time t; associated with an actually selected time marker, characterized in that it comprises: a step of extracting (92) an image of the sequence corresponding to a specific instant t ;, and - a generating step (94) the extracted image corresponding to the specific time l associated with this marker. Method according to claim 7, characterized in that it comprises: a step (126) of moving a cursor in the image in response to displacement commands, this cursor being able to point to one of the markers a step (132) for acquiring a validation signal, and a step (136) for controlling the reader so that the latter begins to read the film directly from the instant t; associated with the marker pointed by the cursor at the time of acquisition of the validation signal. 9. Method according to claim 8, characterized in that the method comprises a step (94) of controlling the display of a marker table formed by several rows and several columns, each row and each column containing a succession of markers arranged in chronological order, times t; associated with each marker of the same line forming an arithmetic progression of reason ri and the instants t; associated with each marker of the same column forming an arithmetic progression of reason r2. 10, Method according to claim 9, characterized in that the reasons ri and r2 are different from each other. 11. Recording medium, characterized in that it comprises instructions for the execution of a method according to any one of claims 7 to 10, when these instructions are executed by an electronic computer. 12. Computer program, characterized in that it comprises instructions for the execution of a method according to any one of claims 7 to 10, when these instructions are executed by an electronic computer. 13. Signal bearing data representative of at least one image produced by means of composite image generation included in a reading device according to one of claims 1 to 4.